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Atmos. Chem. Phys. Discuss., 9, 20429-20469, 2009
www.atmos-chem-phys-discuss.net/9/20429/2009/ doi:10.5194/acpd-9-20429-2009 © Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. |
Three-dimensional numerical simulations of the evolution of a contrail and its transition into a contrail-cirrus
1European Centre for Research and Advanced Training in Scientific Computation, URA CNRS/CERFACS no 1875, Toulouse, France
2Météo France, Toulouse, France
*now at: Department of Geography, King's College London, London, UK
Abstract. This study describes high-resolution numerical simulations of the evolution of an aircraft contrail and its transition into a contrail-cirrus. The contrail is modeled as a vortex pair descending in a stratified atmosphere where turbulent fluctuations are sustained in the late regime of diffusion. The focus of this study is laid on the three-dimensional vortex dynamics – including vortex instability and turbulence – and on the interaction between dynamics and microphysics and its role in determining the growth and the distribution of ice crystals. The results show the feasibility of three-dimensional simulations of the entire lifetime of a contrail until its transformation into a contrail-cirrus in supersaturated conditions. In particular, it is shown that the contrail-cirrus optical depth is maintained as the cloud expands, in agreement with available observations.
Citation: Paugam, R., Paoli, R., and Cariolle, D.: Three-dimensional numerical simulations of the evolution of a contrail and its transition into a contrail-cirrus, Atmos. Chem. Phys. Discuss., 9, 20429-20469, doi:10.5194/acpd-9-20429-2009, 2009.